The application relates to an apparatus for controlling the outlet cross-section of a vent opening for an airbag module.
An airbag module typically includes a gas bag and a gas generator for inflating the gas bag in case of a collision, so that the inflated gas bag forms a gas cushion for protecting an occupant of the vehicle. The gas cushion acts as a restraining device which dampens the impact on an occupant, and especially prevents a direct impact of the occupant against certain injurious parts of the vehicle.
The optimum internal pressure of the gas bag in the inflated state, so as to protect an occupant against injury, is dependent upon a number of parameters, for example the size and weight of the occupant to be protected, the position of the occupant at the moment of a collision, and the nature and gravity of the accident. It is therefore expedient to provide on the airbag module, such as on the gas bag or another component of the airbag module (for example, at a connection between the gas generator and the gas bag), including exhaust or vent openings through which gas can flow out from the airbag module, especially from the inflated or yet-to-be-inflated gas bag. Furthermore, the at least one vent opening, through which gas (produced by the gas generator of the airbag module and originating from the airbag module) can flow away into the environment, can also be arranged outside of the airbag module, especially on a vehicle part containing the airbag module, for example a back-rest of a vehicle chair in the case of a side-airbag module.
The amount of gas released from the gas generator for the inflation of the gas bag is so chosen that it permits the production of the maximum internal pressure in the gas bag, which at certain values of the above-stated parameters proves optimum for the protection of an occupant. In the presence of other values of the above-stated parameters, exhaust or vent openings provided on the airbag module can then serve for reducing the internal pressure in the gas bag, advantageously at certain points in time during and/or after the inflation of the gas bag. For this purpose, it is known to vary the exhaust cross section of a particular vent by varying the position of a covering part with which the vent can be covered, by means of an associated actuating mechanism, such that the vent opening will have a cross section adapted to the values of the above-stated parameters.
The present invention is addressed to the problem of improving an actuating mechanism by which the exhaust cross section of a vent opening will be adjustable, especially in regard to the possibility of a flexible integration of the actuating mechanism into an airbag.